The purpose of the proposed contract is to provide for additional follow-up of 800 women who have participated in a sexually transmitted disease (STD) clinical trial. Using stored blood specimens and sexual history and contraceptive use histories from an ongoing clinical trial, rates of HTLV-III seroconversion among sexually active females will be ascertained. This population of low socioeconomic status women will serve as a sentinel of how rapidly HTLV-III is being introduced into a high risk population, living in a low risk area, during the period of HTLV-III entry into the United States.